Manually-controlled circuit breaker tripping arrangement



Aug; l, 1967 u. R. TOGNELLA MANUALLY-CONTROLLED CIRCUIT BREAKER TRIPPINGARRANGEMENT Filed Feb. ll, 1966 2 Sheets-Sheet i /NvE/vToR: Uso R.Toe/vE/ L/i,

ATTORNEY U. R. TOGNELLA Aug. 1, v1967 MANUALLY-CONTRQLLED CIRCUITBREAKER TRIPPING ARRANGEMENT Filed Feb. ll, 1966 2 Sheets-Sheet 2 UnitedStates Patent O 3,334,202 MANUALLY-CGNTROLLED CIRCUIT BREAKER TRIPPINGARRANGEMENT Ugo R. Tognella, Philadelphia, Pa., assignor to GeneralElectric Company, a corporation of New York Filed Feb. 11, 1966, Ser.No. 526,828 6 Claims. (Cl. 200-82) This invention relates to amanually-controlled tripping arrangement for an electric circuitbreaker, especially a Huid-operated circuit breaker. More particularly,the invention relates to a tripping arrangement of this type thatautomatically resets after circuit-breaker opening but is notsusceptible to pumping i.e., unintentional repetitive operations shouldthe operator continue holding the trip-initiating element in itsoperated position.

Various arrangements have been proposed for manually tripping suchcircuit breakers. Most of these arrangements have relied upon electricalmeans for resetting the tripping arrangement and for preventing theabove- 'described pumping. Such schemes operate satisfactorily ifelectric power is available at the time of tripping, but sometimes noelectrical power is then available.

An object of my invention is to provide a manuallycontrolled trippingarrangement that is capable of automatically resetting and of providingpump-free operation without reliance upon electrical power.

Another object is to provide a manually-controlled tripping arrangementof this type which is capable of preventing an attempted tripping-openoperation should the circuit breaker already be in open position.

In carrying out my invention in one form, I provide a chargeable springthat can be discharged to supply valveoperating force -for operating anopening-control valve that initiates circuit-breaker opening. Latchingmeans is provided for holding the spring in a charged condition and isoperable to initiate discharge of the spring upon receiving alatch-operating force. For operating the latch, manual means is providedcomprising an input member and a force-transmitting mechanism betweenthe` input member and the latching means normally capable oftransmitting a latch-operating force between said input member and saidlatching means. The force-transmitting mechanism has a disabledcondition in which it is incapable of transmitting a latch-operatingforce to the latching means and is incapable of blocking resetting ofthe latching means. Mechanism-control means sensitive to the position ofthe circuit breaker is provided for placing the force-transmittingmechanism in a disabled condition when the circuit breaker is open andfor restoring the force-transmitting mechanism to its normalforcetransmitting condition when the circuit breaker is closed.

Fluid-operated resetting means responsive to circuitbreaker opening isprovided -for recharging the spring and for returning theopening-control valve to its normal position after the circuit-breakeropening. Latch-resetting means operable when the circuit breaker is openis provided for resetting the latching means to a position to hold thespring charged.

For a better understanding of the invention, reference may be had to thefollowing description taken in conjunction with the accompanyingdrawings, wherein:

FIG. V1 is a schematic showing of a tripping arrangement embodying oneform of the invention. The parts are shown in a position occupied whenthe circuit breaker is closed.

FIG. 2 is a schematic showing similar to that of FIG. 1

except showing the parts immediately upon the comple- 3,334,202 PatentedAug. 1, 1967 FIG. 4 is a schematic showing of the invention as appliedto a polyphase circuit breaker.

Referring now to FIG. l, there is shown a high voltage circuit breakerwhich comprises a set of relatively movable contacts 10 connected in ahigh voltage power line 14. The set of contacts 10` comprises a pair ofspacedapart stationary contacts 20 and a relatively movable Contact 21bridging the stationary contacts when in its closed position depicted inFI-G. l. The movable bridging contact 21 is held in its closed positionby heavy spring means 25 urging the bridging contact downwardly.

Upward opening motion of the movable bridging contact 21 is produced bya iluid operator 26. This iiuid operator 26 comprises a cylinder 27 anda piston 29 mounted for reciprocation within the cylinder. Whenpressurized fluid is supplied to the cylinder space beneath the piston29, the piston is driven upwardly, thereby separating the movablebridging contact 21 from its mating stationary contact 20 and openingcircuit 14. When the movable bridging contact reaches its fully openposition (shown in FIG. 2), a hold-open latch 30 is driven into alatching position to hold the movable bridging contact in its fully-openposition. The hold-open latch 30 is driven into and held in its latchingposition of FIG. 2 by a-spring 32.

The pressurized fluid for driving the piston 29 through its openingstroke is derived from a high pressure source (not shown) which suppliesthe pressurized fluid through a supply line 35. For controlling the flowof pressurized fluid through this line 35, a three-way opening-controlvalve 37 is provided. In its closed position of FIG. 1, thisopening-control valve blocks pressurized fluid from flowing from thesource through line 35. Additionally, in its position of FIG. l, thevalve 37 vents the cylinder space beneath the piston 29 to atmospherethrough the event port 40.

When the valve 37 is operated into its open position, shown in FIG. 2,it blocks flow through the vent port 40 and allows pressurized iluid" toflow through the valve from the source to the fluid operator 26. Theentry of pressurized fluid into the uid operator in response to suchvalve-opening results in the piston 29 moving through an upwardcircuit-breaker opening stroke into the position of FIG. 2.

For operating the opening-control valve 37, a chargeable compressionspring 45 is provided. This spring 45 bears at its upper end against astationary stop and at its lower end against a `lever 46 that ispivotally mounted at its left hand end on a stationary .pivot 47. Theright hand end of the lever 46 is normally latched in its position ofFIG. l by latching means 50 comprising a latch member 52 that cooperateswith a latch roller 53 carried 'by lever 46. When latching means 50 isoperated to release lever 46 (as will soon 'be described), spring 45 isfree to discharge and in doing so, drives lever 46 clockwise about pivot47 into the position of FIG. 2..

For transmitting motion of lever 46 to the movable element of theopening-control valve 37, a linkage 55 is provided. This linkage 55comprises a bell crank 56 pivotally mounted on a stationary pivot 57.One arm of the bell crank 56 is connected to the lever 46 through a link58 that is pivotally connected at its respective opposite ends to thellever 46 and the bell crank 56. The other arm of the bell crank isconnected to the movable element of the opening control valve 37 througha tie .rod 60 and an operating arm 462 attached to the rotatable valveelement of valve 37. When spring 45 discharges, it rotates lever 46clockwise from its position of FIG. 1, pivoting bell crank 56counterclockwise, thus pivoting the valveoper-ating arm 62 in aclockwise direction to open valve 37. This valve-opening permits highpressure fluid to ow into the cylinder space beneath piston 29, therebydriving the piston through its upward circuit-breaker opening stroke.The position of the parts immediately upon completion of this upwardstroke is shown in FIG. 2.

For resetting spring 45 and the opening-control valve 37 to their normalcondition of FIG. 1 when an openingoperation of the circuit breaker hasbeen completed, a reset motor 70 is provided. This reset motor 70comprises a cylinder 71 and a piston 72 slidably mounted therein. Piston72 is mechanically coupled to lever 46 by means of a link 74 pivotallyconnected at 75 and 76 to the piston and lever, respectively.

Pressurized fluid is supplied to the reset motor 70 in response tocompletion of a circuit-breaker opening operation. This iluid issupplied to the reset motor 70 through a reset line 718 that isconnected between the cylinders 27 and 71. At one lof its ends, thisreset line 78 communicates with cylinder 71 through a port 80 which isnormally isolated by the piston 29 from pressurized fluid in thecylinder 27. This port 80 is uncovered only at the en-d of acircuit-breaker opening operation. When this occurs, pressurized iluidflows through reset line 78 to the cylinder space 82 beneath resetpiston 72. The entry of pressurized iluid into cylinder space '82 drivesthe piston 72 upwardly from its position of FIG. 2, returning it to itsposition of FIG. l. Such upward movement of piston 72 recharges thespring 45 `and operates the linkage 55 to restore the opening-controlvalve 37 to its normal position of FIG. l. When the opening controlvalve 37 is restored to its position of FIG. l, it vents the spacebeneath the circuitbreaker opening piston 29 through port 40. Inaddition, the pressurized iluid beneath reset piston 72 quickly leaksfrom the cylinder space 82 through a bleed passage 84.

In a preferred form of the invention, a check valve 85 is located in thereset passage 78 to prevent pressurized fluid from being vented toorapidly from the cylinder space 82 at the end of a resetting operation.The presence of the check valve 85 forces such venting to occur throughthe restricted bleed `84, thus slightly delaying restoration of normallow pressure in the space `82. This slight -delay insures that thelatching means 50 will have sufficient time to reset to its position ofFIG. l at the end of a spring-recharging operation before normal lowpressure is restored in cylinder space 82 of the reset motor 70.

The latching means 50 comprises the latching member 52, which ispivotally mounted on a stationary pivot 90, and spring means 91 biasingthe latch member 52 in a counterclockwise direction about pivot 90against a stop 92. The latch roller 53 bears Iagainst the upper end ofthe latch member 52 when the latch member is holding the spring 45 inits charged condition of FIG. l. When the latch member 52 is pivotedclockwise about pivot 90, roller 53y is released and spring-driven lever46 moves clockwise into its position of FIG. 2. While in the position ofFIG. 2, the reset spring 91 attempts to reset the latch member 52.to itsposition of FIG. 1 but is blocked by roller 53 from doing so.

The above-described release of latch member 52 can be effected manuallyby means of -a manually-controlled trip rod 100. This trip rod 100 isslidably mounted on a stationary panel 101 through which it extends. Areset spring 103 bearing against stationary panel 10'1 urges the triprod 100 to the right. When the trip r-od is moved to the left from itsposition of FIG. 1, it acts through a forcetransmitting mechanism 110 tolapply a tripping force to latch member 52.

The force-transmitting mechanism 110 comprises a lever 112 mounted forpivotal motion about a stationary pivot 114 located near its upper end.The spring 103 normally biases this lever"112 counter-clockwise toward astop '117. The lower end of lever 112 is pivotally 'connected to thetrip rod 100 by -a pivot pin 115. At an intermediate point along itslength, the lever 112 carries a pivot 116 on which a thrust member 120is pivotally mounted. This thrust member 120 is biased in a clockwisedirection about pivot 116 by a light tension spring 122. A stop 124 onthe lever 112 limits such clockwise motion -of thrust member 120 on thelever A112. A roller 125 at the left hand end of thrust member 120 isadapted to engage a cam surface 126 on the lower end of lthe latchmember 52 and to transmit tripping force to the latch member 52 in amanner soon to be described.

The force-transmitting mechanism has a force-transmitting condition inwhich it is normally maintained by a mech-anism-cont-rol member 130 thathas a position responsive to the position of the circuit breaker. Thismember 130 is mounted for vertical motion within a guide 131. When thecircuit breaker is closed, as shown in FIG. 1, the mechanism controlmember 130 is maintained-in the depressed position of FIG. 1. When thecircuit breaker opens, however, the mechanism control member 130 ismoved upwardly into its elevated position of FIG. 2. When in thedepressed position of FIG. l, the mechanism control member 130substantially prevents the thrust member 120 from pivoting clockwiseabout its pivot 116. When this clockwise motion of thrust member 120 isblocked, the force-transmitting mechanism 110 is in ayforce-transmitting condition. v

Assume the circuit breaker is in its closed position and the trippingrod 100 is moved to the left from its position of FIG. 1. This Imovesthe lever 112 clockwise about its pivot 114, driving roller 125 onthrust member 120 into engagement with cam 126 on latching member 52.This engagement between cam 126 and roller 125 tends to pivot the thrustmember counterclockwise about its pivot 116 against the bias of lightspring 122. But such counterclockwise motion of thrust member 120 isblocked by the depressed mechanism control member 130. This blockingenables the force-transmitting mechanism 110 to apply an effectivelatch-operating force to latch member 52, thereby forcing latch member52 clockwise into its releasing position of FIG. 2. This sets intomotion the above-described chain of events which results in opening ofthe circuit breaker.

When the circuit breaker opens, mechanism-control member 130 movesupwardly from its position of FIG. 1 into its position of FIG. 2. This,effect, disa'bles the force-transmitting mechanism 110. In its disabledcondition, the force-transmitting mechanism 110 is inelfective toprevent resetting of latch member 52 to its latching position of FIG. lor 3 and is also ineffective to apply a latch operating force to thelatch member 52. Thus, even if the operator continues to hold the triprod 100 in its position of FIG. 2 after circuit-'breaker opening, thelatch member 52 is free to reset to its position of FIG. 1 or 3 withoutinterference from the disabled force- I transmitting mechanism 110. Noadditional operation of the latch member 52 would result from the triprod 100` being held in its operated position while the latch member 52resets because latch-member-resetting moved the thrust member 120` intoits position of FIG. 3 and no effective latch-operating force is beingapplied through the then-disabled force-transmitting mechanism to thelatch member 52.

When the circuit breaker is open, no additional tripping operations oflatch mem'ber 52 will result if the Operator, after releasing the triprod 100, again moves it to the trip position. This is the case becausethe circuit breaker, being open, has lifted the mechanism-control member130 to its position of FIG. 2, thereby disabling the force-transmittingmechanism 110. When the forcetransmitting mechanism 110 is in thisdisabled condition, operation of trip rod 100 into its operated position(of FIG. 3) by an operator simply results in the thrust membercollapsing counterclockwise about its pivot 116 when the roller 125engages the cam 126 on latch member 52. The spring 122 on the thrustmember, being light in comparison to the heavy reset spring 91 on latchmember 52, can provide no eiTective opposition to this counterclockwisecollapse'of the thrust member 12,0.

Thus, the heavy yreset spring 91 holds the latch member 52 in itslatched position of FIG. 3 while the thrust member collapsescounterclockwise into its position of FIG. 3 as explained.

It will be apparent from the above description that my trippingarrangement includes means (78, 70) for automatically resetting all thetrip-controlling parts after a manually-initiated circuit-breakeropening operation and that this resetting can take place despite anoperators holding trip-initiating member 100 in its operated position.Such resetting produces no pumping, i.e., additional tripping operationsdespite the operators holding member 100 in-its operated position. Evenif the operator releases member 100 and returns it to its trippingposition while the circuit breaker is open, no attempted tripping willoccur since the latch member 52 remains in its latching position. Itwill be further apparent that the above-described resetting andpump-free operation has been obtained without reliance upon anyelectrical controls. Thus, my tripping arrangement can operate asabove-described even though no electrical power is available.

It should be understood that FIGS. 1 and 2, being schematic, do not showa true relative size relationship between the tripping arrangement andthe fluid operator 26. In an actual apparatus, the operator 26 is muchlarger relative to t-he tripping arrangement than is illustrated.

When the circuit breaker is closed after the abovedescribed opening, themechanism control member 130 is driven downward into its position ofFIG. l, thereby restoring the force-transmittinng mechanism 110 to itsnormal force-transmitting condition. A closing operation is eiected byreleasing the hold-open latch 30 to allow closing spring 25 to drive thebridging contact 21 downward into its closed position of FIG. l. Suchrelease of the latch 30 can Abe effected by means of a suitable elec-4tromagnet 140 which, when energized, drives the latch 30 out ofrestraining relationship with the movable circuit breaker contact.

For initiating a `closing operation, a closing control circuit 142 isprovided. This circuit comprises a closingcontrol switch 144 in serieswith the coil of electromagnet 140. A conventional interlock switch 146controlled from the trip rod 100 in a conventional manner (not shown) isalso connected in series with electromagnet 140. This interlock switch146 opens in response to a manually initiated circuit-breaker openingoperation and remains open until deliberately reset by the operator.Thus, the interlock switch 146 serves to prevent an inadvertent'electrically-initiated circuit-breaker closing operation. Aconventional b switch 148, which opens when the circuit breaker closesbut closes when the circuit breaker opens, is used for preventingoperation of the hold-open latch 30 when the circuit breaker is in itsopen position of FIG. 1.

Although the invention has been described hereinabove in connection witha single phase circuit breaker it is equally applicable to a polyphasebreaker. For example, in FIG. 4, I show a three-phase circuit breakerembodying thel invention. This circuit breaker comprises a iirst set ofcontacts identical to the contacts of FIG. 1 connected in one phase 14of a polyphase circuit. It further comprises additional sets of contacts11 and 12 respectively connected in the additional phases 15 and 16 ofthe power circuit. These sets of contacts 11 and 12 correspond instructure to the set 10. Each set of contacts has its own uid operatorcorresponding to the fluid operator 26 of FIG. 1. The uid operators forthe respective phases are designated 26, 26a and 26h. Only the iiuidoperator for one phase of the circuit breaker has the reset passage 78connected thereto. Each fluid operator has its own opening controlvalve, and these are respectively designated 37, 37a, and 37b. Theseopening control valves each operate in the same manner as the openingcontrol valve 37 of FIG. 1. The apparatus of 6 FIG. 4 individual to asingle phase of the circuit is referred to hereinafter as a pole unit.

All of the opening-control valves are mechanically coupled together by atie link 60a pivotally connected to the operating arms 62 of the valves.Thus, when the rod 60 is moved to the left, as explained in connectionwith FIG. l, it simultaneously opens all three of the openingcontrolvalves. This causes the three uid operators 26, 26a and 26b tosimultaneously drive their associated sets of contacts through anopening stroke. The mechanical tie 60a between the three opening-controlvalves facilitates simultaneous operation of the three pole units of thecircuit breaker. In one embodiment of the invention, the three poleunits open their contacts within .O05 second of each other.

Each set of contacts has its own hold-open latch corresponding to thelatch 30 of FIG. l. These latches are respectively designated 30, 30a,and 30b. Closing is effected by tripping these latches simultaneously toallow the closing springs associated with three sets of contacts toeffect simultaneous closing. The closing electromagnets are shownconnected in parallel with each other and in series with a closingcontrol switch 144, a "b switch 148, and an interlock switch 146corresponding to similarly-designated switches in FIG. l.

A single tripping spring 45 (not shown) corresponding to the spring 45of FIG. 1 is used for controlling all three of the opening controlvalves 37, 37a, 37b, and resetting of such spring 45 can be controlledby the position of only one of the Huid-operators 26. For this reasononly a single reset line 78 is used in the embodiment of FIG. 4. Thesingle tripping spring 45Awhich is used in the embodiment of FIG. 4 iscontrolled in the same manner as depicted in FIG. l.

While I have shown and described particular embodiments of my invention,it will be obvious to those skilled in the art that various changes andmodifications may be made without departing from my invention in itsbroader aspects; and I, therefore, intend in the appended claims tocover all such changes and modications as fall within the true spiritand scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates are:

1. In an electric circuit breaker comprising a uid operator for openingthe circuit breaker when pressurized fluid is supplied to the operator,the combination of:

(a) an opening-control valve for admitting pressurized iiuid to saidoperator when in one position and for venting said operator when inanother position,

(b) la chargeable spring dischargeable to supply valveoperating forcefor operating said opening-control valve from said one position to saidother position,

(c) linkage means for transmitting said valve-operating force from saidspring to said control valve,

(d) latching means for holding said spring in a charged condition andoperable to initiate discharge of said spring upon receiving alatch-operating force,

(e) manual means for operating said latching means comprising an inputmember and a force-transmitting mechanism between said input member andsaid latching means normally capable of transmitting a latch-operatingforce between said input member and said latching means,

(f) said force-transmitting mechanism having a disabled condition inwhich it is incapable of transmitting a latch-operating force to saidlatching means and is incapable of blocking resetting of said latchingmeans,

(g) mechanism-control means sensitive to the position of said circuitbreaker for placing said force-transmitting mechanism in said disabledcondition when said circuit breaker is open and for restoring saidforcetransmitting mechanism to its normal force-transmitting conditionwhen said circuit breaker is closed,

(h) Huid-operated resetting means responsive to opera- 7 -tion of `saidfluid operator into a circuit-breaker open position for recharging saidspring and for returning said opening-control valve to said oneposition,

(i) and latch-resetting means operable when the circuit breaker is openfor resetting said latching means to a position to hold said springcharged.

2. The combination of claim 1 in which:

(a) said force-transmitting mechanism comprises a thrust member throughwhich latch-operating force can be applied when said thrust Imember isrestrained against a predetermined motion, said thrust member beingincapable of applying latch-operating force when said restraint isremoved,

(b) said mechanism-control means comprises means for restraining saidthrust member against said predetermined motion when said circuitbreaker is in closed position and for removing said restraint when saidcircuit breaker is in open position.

3. The combination of claim 1 in which:

(a) said force-transmitting mechanism comprises a movable lever and athrust member pivotally mounted on said lever, said force-transmittingmechanism being in its disabled condition when said thrust member isfree to pivot on said lever,

(b) said latching means includes a cam tending to produce pivotal motionof said thrust memeber on said lever when said force-transmittingmechanism is opperated by said manual means, and

(c) said mechanism-control means comprises means for blocking saidthrust member from pivoting `on said lever when said circuit breaker isclosed and for allowing said thrust member to pivot on said lever whensaid circuit breaker is open.

4. In an electric circuit breaker comprising motive means for openingsaid circuit breaker when an openincontrol element is operated,

(a) a chargeable spring dischargeable to effect operation of saidopening-control element,

(b)v means for transmitting operating force from said spring to saidopening-control element,

(c) latching means for holding said spring in a charged condition andoperable to initiate discharge of said spring upon receiving alatch-operating force,

(d) manual means for operating said latching means comprising an inputmember and a force-transmitting mechgnism between said input member andsaid latching means normally capable of transmitting a latch-operatingforce between said input member and said latching means,

(e) said force-transmitting mechanism having a disabled condition inwhich it is incapable of transmitting a latch-operating force to saidlatching means and is incapable of blocking resetting of said latchingmeans,

(f) mechanism control means sensitive to the position `of said circuitbreaker for placing said force-transmitting mechanism in a disabledcondition when said circuit breaker is opened and for restoring saidforcetransmitting mechanism to its normal force-transmitting conditionwhen said circuit breaker is closed,

(h) resetting means responsive to operation of said motive means into acircuit-breaker open postiion for recharging said spring,

(i) and latch-resetting` means operable when the circuit breaker is openfor resetting said latching means to a position to hold said springcharged.

5. The combination of claim 4 in which:

(a) said force-transmitting mechanism comprises a thrust member throughwhich latch-operating force can be applied when said thrust member isrestrained against a predetermined motion, said thrust member beingincapable of applying latch-operating force when said restraint isremoved,

(b) said mechanism-control means comprises means for restraining saidthrust member against said predetermined motion when said circuitbreaker is in closed position and for removing said restraint when saidcircuit breaker is in open position.

6. The combination of claim 1 in which:

(a) said circuit breaker comprises a plurality of pole units each havingits own fluid operator and its own opening-control valve for its fluidoperator,

(b) a mechanical tie is provided between said openingcontrol valves, l f

(c) said spring acts through said tie to vproduce simultaneous valveoperation upon spring discharge, and

(d) said fluid-operated resetting means operates to return saidplurality of openingcontrol valves to their venting position.

References Cited UNITED STATES PATENTS 2,676,285 4/1954 Jumscm etal.20o-81,16d X 2,730,590 1/1956 Kelle 20o-82a 2,778,379 1/1957 Timmerman20o-148.6 2,920,170 1/1960 Caswell 20d- 148.6 3,062,934 11/1962 Nijemd200-s2.1 3,113,191 12/1963 Frank 20o-153.8

ROBERT K. SCHAEFER, Primary Examiner.

H. HOHAUSER, Absistant Examiner.

4. IN AN ELECTRIC CIRCUIT BREAKER COMPRISING MOTIVE MEANS FOR OPENINGSAID CIRCUIT BREAKER WHEN AN OPENINCONTROL ELEMENT IS OPERATED, (A) ACHARGEABLE SPRING DISCHARGEABLE TO EFFECT OPERATION OF SAIDOPENING-CONTROL ELEMENT, (B) MEANS FOR TRANSMITTING OPERATING FORCE FROMSAID SPRING TO SAID OPENING-CONTROL ELMENT, (C) LATCHING MEANS FORHOLDING SAID SPRING IN A CHARGED CONDITION AND OPERABLE TO INITIATEDISCHARGE OF SAID SPRING UPON RECEIVING A LATCH-OPERATING FORCE, (D)MANUAL MEANS FOR OPERATING SAID LATCHING MEANS COMPRISING AN INPUTMEMBER AND A FORCE-TRANSMITTING MECHANISM BETWEEN SAID INPUT MEMBER ANDSAID LATCHING MEANS NORMALLY CAPABLE OF TRANSMITTING A LATCH-OPERATINGFORCE BETWEEN SAID INPUT MEMBER AND SAID LATCHING MEANS, (E) SAIDFORCE-TRANSMITTING MECHANISM HAVING A DISABLED CONDITION IN WHICH IT ISINCAPABLE OF TRANSMITTING A LATCH-OPERATING FORCE TO SAID LATCHING MEANSAND IS INCAPABLE OF BLOCKING RESETTING OF SAID LATCHING MEANS, (F)MECHANISM CONTROL MEANS SENSITIVE TO THE POSITION OF SAID CIRCUITBREAKER FOR PLACING SAID FORCE-TRANSMITTING MECHANISM IN A DISABLEDCONDITION WHEN SAID CIRCUIT BREAKER IS OPENED AND FOR RESTORING SAIDFORCETRANSMITTING MECHANISM TO ITS NORMAL FORCE-TRANSMITTING CONDITIONWHEN SAID CIRCUIT BREAKER IS CLOSED, (H) RESETTING MEANS RESPONSIVE TOOPERATION OF SAID MOTIVE MEANS INTO A CIRCUIT-BREAKER OPEN POSITION FORRECHARGING SAID SPRING, (I) AND LATCH-RESETTING MEANS OPERABLE WHEN THECIRCUIT BREAKER IS OPEN FOR RESETTING SAID LATCHING MEANS TO A POSITIONTO HOLD SAID SPRING CHARGED.